Reaction vessel for use in photometric measurements

ABSTRACT

A small vessel having generally cylindrical form is described. This vessel has a flange at the upper rim and the lower portion is provided with parallel planar surfaces particularly suitable for photometric measurement of the contents of the vessel.

United States Patent Inventor Wilhelm Bergmann Hamburg, Germany Appl.No. 820,231 Filed Apr. 29, 1969 Patented Dec. 14, 1971 AssigneeEppendorf Geraetebau Netheler & Hinz Gmbl-l Hamburg, Germany PriorityMay 2, 1968 Germany REACTION VESSEL FOR USE IN PHOTOMETRIC MEASUREMENTS12 Claims, 4 Drawing Figs.

U.S. Cl 356/246, 23/292, 250/218 Int. Cl GOln 1/10 Field of Search356/244, 246; 250/218; 23/292 References Cited UNITED STATES PATENTS2/1946 Strickland 2,397,846 4/1946 Dietert 23/292 3,246,559 4/1966Clifford, Jr. 356/246 3,263,554 8/1966 Pickels 356/246 3,286,583 11/1966Ferrari 356/246 3,363,503 H1968 Shifrin 356/246 FORElGN PATENTS 578,8076/1933 Germany 356/246 OTHER REFERENCES Henderson et al., Analyt. Chem.,Vol. 31, No. 12, Dec., 1959,pg. 2113 Primary Examiner-Ronald L. WibertAssislant Examiner-Warren A. Sklar AttorneysJohn C. McGregor, James A.Eisenman and Robert R. Strack ABSTRACT: A small vessel having generallycylindrical form is described. This vessel has a flange at the upper rimand the lower portion is provided with parallel planar surfacesparticularly suitable for photometric measurement of the contents of thevessel PATENTEI] DEC] 41% Fig. 2

Fig. 3

INVI'JN'IUR.

WILHE LM BERG MANN aim Md 6 1* REACTION VESSEL FOR USE IN PHOTOMETRICMEASUREMENTS BACKGROUND OF THE INVENTION This invention relates toreaction vessels, and more particularly to reaction vessels adaptablefor use in the photometric measurement of small quantities of liquids.

Small quantities of liquid are often handled in reaction vessels havinga height of approximately 30 mm. and a diameter of approximately mm.Such vessels are generally of cylindrical form and have an upper flangerim providing a shoulder which facilitates handling. Such vessels are ofparticular usefulness in connection with automatic processing systemswherein the transfer of the vessel and the agitation and treatment ofthe contents are simplified by the cylindrical form. These vessels arefrequently made of plastic and are dispensable so that they need be usedonly once. In general the vessels have heretofore been used formechanical treatment of the contents only. When it is necessary ordesirable to execute photometric measurements of the contents, inparticular, comparison measurements, special measuring cuvettes must beemployed. The contents of the original vessel are transferred into thesemeasuring cuvettes in order to assure that the optical properties of thevessel exhibit desired characteristics.

SUMMARY OF THE INVENTION The present invention provides a reactionvessel which is not only particularly well suited for the mechanicaltreatment of the contents thereof, but at the same time may be employedas a cuvette suitable for making photometric measurements.

The vessel of the present invention exhibits in cross section a pair ofparallel planar walls on opposing sides. These walls are disposed alongchords of the circle defined by the upper cylindrical portion of thevessel. Outwardly directed ribs are arranged on the planar surfaces witha space therebetween. These ribs project no further than the peripheryof said cylindrical portions.

By retaining the basic cylindrical form of conventional reactionvessels, the vessels of the present invention are suitable for handlingin automatic systems in the same manner as existing vessels. On theother hand, as a result of the planar surfaces they contain, thesevessels permit measurements to be made photometrically.

An object of the present invention is to provide an improved reactionvessel for both mechanical preparation of the contents and photometricmeasurement thereof.

Another object of the invention is to provide an improved reactionvessel having parallel planar walls.

Another object of the invention is to provide an improved reactionvessel having parallel planar walls and yet retaining a basicallycylindrical configuration relative to the longitudinal axis thereof.

It has been found that the provision of reinforcing ribs of the naturedescribed hereinafter, makes it possible to provide a thin constructionof the planar surface of the vessel without danger of having the planarsurfaces arch following production. It is possible to use ribs whichextend around the circumference of the vessel perpendicular to thelongitudinal axis thereof, however, a particularly preferred form ofconstruction provides ribs which extend in a direction parallel to thevessel axis and are arranged on either side of the planar surface. Bylongitudinally the ribs in this, fashion, the vessel is better adaptedfor insertion into openings or holes and in addition, the ribs providesome shielding of the planar surface on which measurements will takeplace.

Another object of the invention is to provide an improved reactionvessel having thin parallel planar walls and reinforcing ribs.

Another object of the present invention is to provide an improvedreaction vessel particularly adapted for insertion into openings orholes without damaging the planar surfaces.

It has also been found desirable that the wall sections between thepreviously mentioned planar surfaces be also drawn in and arranged asparallel planar surfaces that are orthogonally disposed relative to thefirst mentioned planar surfaces and which also lie along chords of thecircle defined by the cylindrical portion of the vessel. Thus, the samevessel provides two different optical measurement paths. Still further,it is contemplated that the invention provide an inner core section ofthe vessel which is rectangular at least in the region of theaforementioned planar surfaces. This rectangular section and the planesurface section being advantageously adjacent to an upper cylindricalwall section which is directly under a rim flange. Finally, a nose, orbottom portion, of substantially rectangular section is provided at thebottom of the vessel.

Another object of the invention is to provide an improved reactionvessel having two photometric measuring paths.

Another object of the present invention is to provide an improvedreaction vessel having an at least partially rectangular interiorportion in order to provide better mixing in the event of agitation.

Still another object of the present invention is to provide an improvedreaction vessel having good form stability and heat transfercharacteristics.

Yet another object of the present invention is to provide an improvedreaction vessel including means for facilitating alignment of thevessel.

With respect to the last mentioned object, it will be noted that theribs protect the planar surfaces against mechanical contact, scratching,and the like, and thereby provide an important function considering thefact that the vessel may be used for photometric measurements. Theseribs may also be utilized in order to align the vessel for measurement.0n the other hand, there may be provided a rectangular nose portion, orbase portion, at the bottom of the vessel. According to a preferred formof construction, stepped surfaces extend at right angles to thelongitudinal axis of the vessel and are arranged on at least two sidesof the rectangular base. These surfaces make it possible to hold thevessel by the base and support it upon the stepped surfaces so that itis not inserted too deeply into any openings.

Advantageously, the vessel tapers at the bottom, the taper beingproduced essentially by chamfering of the ribs, while the interior ofthe vessel has a constant rectangular cross section extending through tothe bottom. This tapering facilitates the easy introduction of thevessel into openings. It is to be noted however that the planar surfacesdo not participate in this tapering eflect and that they are alwaysparallel with one another.

The above objects and features of the invention will be more clearlyunderstood and appreciated from the following description which is madein connection with the drawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of a vesselembodying the present invention, half of this elevation being in sectionalong the line I-I shown in FIG. 2;

FIG. 2 is a top view of a vessel embodying the present invention;

FIG. 3 is a side elevation of the vessel shown in FIG. 1, rotatedthrough and having a portion in cross section taken along the lineIII-III shown in FIG. 4; and

FIG. 4 is a bottom view of the vessel embodying the invention, half ofsaid view being in section taken along the line IV-IV in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT The figures disclose a vesselwhich is open at the top and which may be provided with a variety ofclosure means. In usual embodiments, the vessel may have a height ofapproximately 30 mm. and the outside diameter of the upper flange rimmay be approximately 18 mm. The upper portion of the vessel includes anoutwardly extending flange 1 below and adjacent to which is a recessedcylindrical wall section 2. Below the cylindrical wall section 2, thevessel walls are disposed inwardly and establish parallel planarsurfaces. Two opposing surfaces 3 and 4 are created having somewhatgreater width than the lateral interconnecting surfaces 5 and 6 whichextend therebetween at right angles. The plane surfaces 3 and 4 havedisposed thereon pairs of perpendicularly extending ribs 7, 8 and 9, 10,which are spaced from the center of the surfaces and extend orthogonallytherefrom to terminate in the outer contour defined by the uppercylindrical portion 2 of the vessel. These ribs may also form a smoothtransition into the cylindrical section 2. The outer edges of the ribsare accordingly designed obliquely to their major axes.

The surfaces 5 and 6 are also flanked by pairs of ribs 11, 12 and 13,14. In this case, the ribs 11-14 lie in prolongation of the wallportions forming the plane surfaces 3 and 4. In accordance with thisdesign, the inner cross section of the vessel at the level of the planesurfaces 3 and 4 is rectangular as illustrated at 15 in FIG. 2. It willalso be noticed from FIGS. 1 and 2 that the transitions 16 and 17 fromthe cylindrical vessel wall section 2 to the section with the innercross section are formed by oblique transition surfaces; the inclinationof the surfaces 16, 17 being different due to the different retractionof the plane surfaces 3 and 4 on the one hand and of the lateralsurfaces 5 and 6 on the other. As a result of this, the ribs 11-14 aresomewhat flatter than the ribs 7-10.

At the bottom of the vessel, there is a projecting nose or base portion18 which has a substantially rectangular cross section. FIG. 4illustrates that the lower limiting edges 19 and 20 under the lateralsurfaces 5 and 6 may be slightly rounded. This results from the amountof taper of the vessel downwardly. In any event, the longer edge 21shown in FIG. 4, and the corresponding edge on the opposite side (notshown), under the plane surfaces 3 and 4 are straight and parallel tothe plane surfaces so that they may be used for alignment of the vessel.

FIGS. 1 and 3 also illustrate that the nose 18 tapers downwardly so thatits introduction into a correspondingly profiled opening may befacilitated. In particular, as shown in FIG. 1, stepped surfaces 22 and23 are provided parallel to the longitudinal edges of the nose 18. Thesesurfaces provide for aligned vertical placement and make it possible toplace a vessel with the nose 18 only in a prepared opening. Thesestepped surfaces may continue into the lower region of the ribs 710 sothat a relatively large support surface is provided.

The taper of the lower vessel edge is produced in particular at thecircumferential sections at which the plane surfaces 3 and 4 arelocated, by chamfers 24 and 25 of the ribs. The vessel body may also bebevelled, as for example at 26 in FIG. 3, this chamfer will lie belowthe bottom surface 27 of the vessel.

A particular embodiment of the invention has been shown and described.Clearly, the dimensions recited herein, and even the relative dimensionsof the various sides of the vessel, are not necessarily germane to theinvention. It is contemoutwardly projecting ribs extendinglongitudinally on each 7 side of said opposed parallel planar wallsdisposed to leave a flat central portion therebetween, the outer edgesof said ribs establishing points on the circumference of a circle, saidcircle being disposed within a transverse plane through said vessel andorthogonal to said axis, whereby the outer edges of said ribs form theoutline of a substantially cylindrical configuration.

2. A reaction vessel according to claim 1, wherein the center of saidcircle lies on said longitudinal axis. h

3. A reaction vessel according to claim 1, wherein said circle has thesame radius as said upper cylindrical portion.

4. A reaction vessel according to claim 1, wherein each of said opposedparallel planar walls comprise planar portions that define chords on acircle disposed within a transverse plane through said vessel andorthogonal to said axis.

5. A reaction vessel according to claim 1, wherein the wall sections ofsaid vessel between said parallel planar walls are opposed parallelplanar lateral surfaces.

6. A reaction vessel according to claim 5, wherein end ribs project fromsaid lateral surfaces as prolongations of said first mentioned parallelplanar walls.

7. A reaction vessel according to claim 1, wherein said vessel tapers atthe bottom, said taper being affected essentially by a chamfer of saidprojecting ribs, and wherein the interior of said vessel has a constantrectangular cross section extending to the bottom thereof.

8. A reaction vessel according to claim I, having substantially equalwall thickness throughout.

9. A reaction vessel according to claim 1, wherein the inner crosssection of the vessel is rectangular at least in the region of saidplanar walls.

10. A reaction vessel according to claim 9, wherein a projecting portionextends from the bottom of the vessel and exhibits a substantiallyrectangular transverse cross section.

11. A reaction vessel according to claim 10, wherein the longer axis ofsaid rectangular cross section extends parallel to said first mentionedparallel planar walls and at least the edges of said projection arestraight in this direction.

12. A reaction vessel according to claim 1 1, wherein at least on twosides of said projecting portion, stepped surfaces extend at rightangles to said longitudinal axis.

1. A reaction vessel suitable for the photometric measurement of smallquantities of liquid, comprising an upper cylindrical portion having alongitudinal axis, a lower portion having opposed parallel planar walls,a connecting portion providing a transition between said upper and lowerportions, and outwardly projecting ribs extending longitudinally on eachside of said opposed parallel planar walls disposed to leave a flatcentral portion therebetween, the outer edges of said ribs establishingpoints on the circumference of a circle, said circle being disposedwithin a transverse plane through said vessel and orthogonal to saidaxis, whereby the outer edges of said ribs form the outline of asubstantially cylindrical configuration.
 2. A reaction vessel accordingto claim 1, wherein the center of said circle lies on said longitudinalaxis.
 3. A reaction vessel according to claim 1, wherein said circle hasthe same radius as said upper cylindrical portion.
 4. A reaction vesselaccording to claim 1, wherein each of said opposed parallel planar wallscomprise planar portions that define chords on a circle disposed withina transverse plane through said vessel and orthogonal to said axis.
 5. Areaction vessel according to claim 1, wherein the wall sections of saidvessel between said parallel planar walls are opposed parallel planarlateral surfaces.
 6. A reaction vessel according to claim 5, wherein endribs project from said lateral surfaces as prolongations of said firstmentioned parallel planar walls.
 7. A reaction vessel according to claim1, wherein said vessel tapers at the bottom, said taper being effectedessentially by a chamfer of said projecting ribs, and wherein theinterior of said vessel has a constant rectangular cross sectionextending to the bottom thereof.
 8. A reaction vessel according to claim1, having substantially equal wall thickness throughout.
 9. A reactionvessel according to claim 1, wherein the inner cross section of thevessel is rectangular at least in the region of said planar walls.
 10. Areaction vessel according to claim 9, wherein a projecting portionextends from the bottom of the vessel and exhibits a substantiallyrectangular transverse cross section.
 11. A reaction vessel according toclaim 10, wherein the longer axis of said rectangular cross sectionextends parallel to said first mentioned parallel planar walls and atleast the edges of said projection are straight in this direction.
 12. Areaction vessel according to claim 11, wherein at least on two sides ofsaid projecting portion, stepped surfaces extend at right angles to saidlongitudinal axis.